https://scholar.archive.org/

https://en.wikipedia.org/wiki/Multi-factor_authentication :

• Something the user has - device/token
• Something the user knows - password/pin
• Something the user is - biometrics

There exists JSONPath

Have you read Worm ( https://parahumans.wordpress.com/ ) or wandering inn ( https://wanderinginn.com/ ) ?

Element is running out of money. I think they would keep the old license if other commercial matrix-based projects would contribute developers or money.